Craft supply has multiple versions of the sketch pencil. Their toolbox pencil has a hex head type feature at the top with some sort of centerband. Their artist sketch pencil is a single tube design with a clip. Everyone seems to have roughly the same pricing.
CSUSA offers the same woodworkers/sketch pencil that WC & PSI offer only CS offers it it three finishes. (505-5007, 050-5008, 050-5009) Gold, Chrome & Black at $8.50 a copy.http://www.woodturnerscatalog.com/cgi-bin/shopper?search=action&keywords=artist-sketch-pencil
WC (#146767) is $7.99 available in gold only
PSI (PKSPCL) is $7.95 in gold only and the style is different